Production of alpha-naphthyl methanesulfonate esters

ABSTRACT

Disclosed herein is a method of preparing alpha-naphthyl esters by the oxidation of naphthalene with bis-(methanesulfonyl peroxide). High ratios of the alpha to the beta-ester are prepared at high efficiencies and at reasonable temperatures by selecting certain solvents and by controlling certain other reaction variables. The alpha-naphthyl esters can be easily converted to alpha-naphthol.

United States Patent Muratorio [151 3,674,830 [4 July4,1972

[54] PRODUCTION OF ALPHA-NAPHTHYL METHANESULFONATE ESTERS [72] Inventor:Jorge R. Muratorio, Buenos Argentina I73 I Assigncc: CelunescCorporation, New York, NY.

[22] Filed: Sept. 24, 1969 [21 Appl. N0.: 860,838

Aires,

[52] U.S.Cl ..260/456 P, 260/618 F [51] Int. Cl ..C07c 143/68 [58] Fieldof Search ..260/456 R, 456 P 814, (1959) (Allyn and Bacon, Inc.)

Suter, The Organic Chem. of Sulfur," pp. 268- 272 (1944, Wiley) Hatch,Chemistry of Naphthalenes, Hydrocarbon Processing and PetroleumRefinery, Vol. 42, (3) 113 118 (1963) Primary Examiner-Leon ZitverAssistant ExaminerL. B. De Crescente Att0rneyD. J. De Witt, M. Turkenand K. W. Vernon [5 7] ABSTRACT Disclosed herein is a method ofpreparing alpha-naphthyl esters by the oxidation of naphthalene withbis-(methanesulfonyl peroxide). High ratios of the alpha to thebeta-ester are prepared at high efficiencies and at reasonabletemperatures by selecting certain solvents and by controlling certainother reaction variables. The alpha-naphthyl esters can be easilyconverted to alpha-naphthol.

2 Claims, N0 Drawings PRODUCTION OF ALPHA-NAPHTHYL METHANESULFONATEESTERS This application is a continuation of U.S. application Ser. No.566,239, filed July 19, 1966, now abandoned. This invention relatesbroadly to the production of predominantly alphanaphthyl esters. Moreparticularly this invention is concerned with the preparation ofpredominantly alpha-naphthyl esters and alpha-naphthol by the oxidationof naphthalene with bis- (methanesulfonyl peroxide).

The sulfonation of naphthalene is known and has been studied extensivelyfor quite a number of years. For example, alpha-naphthalene sulfonicacid has been prepared by the sulfonation of naphthalene usingconcentrated sulfuric acid and chlorosulfonic acid. Commercially it hasbeen prepared by sulfonating naphthalene with about 98 percent sulfuricacid using seed crystals of alpha-naphthalene sulfonic acid.

The process as herein described constitutes an efficient cyclic processfor the production of predominantly alpha-- naphthylmethanesulfonatewhich can be readily hydrolyzed to alpha-naphthol, a valuableintermediate in the production of certain insecticides.

Prior to this invention it was known that aromatic compounds could beoxidized with bis-(lower alkane sulfonyl peroxides) such asbis-(methane-sulfonyl peroxide), with the formation of aromatic esters.Such a process is described, for example, in U.S. Pat. No. 3,320,301filed Sept. 18, 1963, assigned to the assignee of the presentapplication.

It has been unexpectedly found that naphthalene can be oxidized withbis-(methanesulfonyl peroxide) to form naphthyl esters with the ratio ofthe alphato the beta-ester being at least about 8. This was totallyunexpected as it would be thermodynamically expected that a predominantamount of the ,8- ester would be formed.

It is an object of this invention to produce predominant amounts ofalpha-naphthyl esters at high efficiencies and at reasonabletemperatures.

It is a further object of this invention to continuously producealpha-naphthol from naphthalene by oxidizing naphthalene withbis-(methanesulfonyl peroxide) to the naphthyl ester and hydrolyzing theester to the corresponding naphthol.

Specifically, this invention comprises oxidizing naphthalene withbis-(methanesulfonyl peroxide) in the presence of a solvent for bothnaphthalene and bis(methanesulfonyl peroxide) under the conditions ofthe reaction and which is chemically inert with respect tomethanesulfonyl peroxide or which is substantially inert tomethanesulfonyl peroxide with respect to naphthalene.

Alpha-naphthyl methanesulfonate, formed by the process of thisinvention, can be hydrolyzed under acidic or alkaline conditions toalpha-naphthol which is a valuable intermediate useful in production ofcertain insecticides. The process of this invention can be illustratedby the following equations below:

(I) Electrolysis 2(CH3SO2OH) H2 (U1138020): 08020113 I m 1133020): m H:SO; H

OSOzQHa OH A @w H2O CHtlSOz H Bis-(methanesulfonyl peroxide) can beprepared by any number of methods; however, for purposes of thisinvention the preparation of bis-(methanesulfonyl peroxide) byelectrolysis is very effective. As shown in the above equation themethanesulfonic acid resulting from the oxidation of naphthalene tothenaphthyl ester can be recycled to regenerate the peroxide or, as wasmentioned before, the ester can be hydrolyzed to yield predominantlyalpha-naphthol and methansulfonic acid, the latter of which can also berecycled to regenerate the peroxide.

In general, the method of the present invention provides a high yield ofthe desired alpha-ester. For example, yields of alpha-ester of 60 to 90percent based on bis-(methanesulfonyl peroxide) have been obtained bythis process.

The method of this invention is carried out in a reaction medium inwhich both naphthalene and bis-(methanesulfonyl peroxide) are soluble atleast to a limited extent. Both naphthalene and bis-( methanesulfonylperoxide) are solids; hence, it is necessary to use a solvent in orderfor the reaction to be carried out at reasonable temperatures. If areactive solvent is used, such as benzene, it must have a reaction ratewith bis-(methanesulfonyl peroxide) at least times less than that ofnaphthalene. Suitable inert solvents which have been found useful in theprocess of this invention include nitrobenzene.

Other solvents which may be used include such compounds as dioxane,acetone, acetic acid, benzene, toluene, etc.

The process of this invention can be carried out continuously,semi-continuously or by a batchwise process. Preferably a continuousprocess is used, especially where the production of predominant amountsof alpha-naphthol are desired.

The temperature has a significant effect on the reaction rate ofnaphthalene to the desired naphthyl ester. The reaction can be conductedat temperatures ranging from 0 C. to about 50 C. More desirably, thereaction is conducted at ambient temperatures ranging from about 15 to40 C. At temperatures above 50 C. there is danger of explosion becauseof the very high reaction rate of the bis-(methanesulfonyl peroxide)with the reactants. Atmospheric, sub-atmospheric or super-atmosphericpressures may be employed, the pressure having no significant efiect onthe reaction. Pressures may range, for ex.- ample, anywhere from 0 to1,000 psig. The molar ratio of naphthalene to bis-(methanesulfonylperoxide) is usually 1:1 but it may range from 0.521 to 10:1. Theconcentration of bis- (methanesulfonyl peroxide) used may constitute aslittle as 0.01 mole per liter of the total amount of the reactionmixture (naphthalene, peroxide and solvent). More may be used, however,the use of larger amounts does not result in any particular advantage.For a batch process the amount of bis- (methanesulfonyl peroxide)generally ranges from about 0.05 to 0.2 mole per liter. Theconcentration of naphthalene ranges from about 0.01 to 0.6 moles perliter.

By the process of the instant invention molar ratios of the alpha tothe'beta naphthyl esters of at least 8 can be obtained at efficienciesranging from 40 to percent.

EXAMPLE 1 Bis-(methanesulfonyl peroxide) was made by the anodicoxidation of 10 M aqueous methanesulfonic acid. A cylindrical containerthree cm. in diameter and 7 cm. deep, cooled by a cold water jacket wasused as an electrolytic cell. The anode, a platinum wire, was rotated toprovide good mixing and to keep precipitated bis-(methanesulfonylperoxide) in suspension. The electrolyte was recirculated in the cellwith the aid of a bellows pump. The suspended peroxide was filtered fromthe electrolyte with a fritted glass filter. The cathode and the anodewere both 0.1 mm. platinum wires, the cathode being 18 cm. long and theanode 64 cm long. About ml. of a 10 M solution of methanesulfonic acidwas fed to the electrolytic cell and the recirculating system. For eachbatch of his- (methanesulfonyl peroxide) prepared, 1.0 amps, was passedthrough the cell for 3 hours at a current density of 0.5 amps/sq. cm.The peroxide separated in the filter was washed with cold water anddried at roomtemperature in a vacuum oven for over 24 hours.

Using the bis-(methanesulfonyl peroxide) prepared as described above,runs were carried out at atmospheric pressures and at room temperature(23 C) using various media as solvents for naphthalene andbis-(methanesulfonyl peroxide). Typically the naphthalene was dissolvedin the. medium separately from the dissolution of thebis-(methanesulfonyl 2. Using nitrobenzene as the solvent andstoichiometric peroxide). After dissolution of both reactants they wereimamounts of the reactants the efficiency based on bismediately mixed.Some reaction between bis-(methanesulfoane y P r Varied fr m between 60n 73 nyl peroxide) and the solvent was observed when acetone and Percentfor h alp n between 2 and 8 percent f r dioxane was used. For exam le,in a solution of 0.4 M bis- 5 the beta-ester. When naphthalene was usedin 100 mole per- (methanesulfonyl peroxide) in dioxane at roomtemperature, eXCeSS with acetone 85 the n h f 50 percent of the peroxidereacted with the dioxane in the first Cieflcies the total esters basednaphthalene were P ten minutes while under the ame o di i l 3 percentcally quantitative. Under the same conditions the yields based of theperoxide reacted when acetone was used as the solvent. n bis-(me ha es yperoxide) were 71 and for lhe No reaction with the peroxide was observedwhen alpha-ester n 6 and 5 p nt for h rnitrobenzene was used as solvent.These results are shown in Table I below.

TABLE I Reaction of MS? with naphthalene Reaction of MSP with the andsolvent olvent Total vol.

- MSP, of reaction M51, a-ester B-ester ltnlio of Initial Tlme, weightCone. ol mixture, Time, weight formed, formed. ato Run No. Solvent cone.min. percent reactants ml. min. percent 1;. 1: li-ester J 0 l 66 1Dioxane 0.4 M I 9" 13. l r) 11.0 N1trobenzene 0.4 M I ma 3 Acetone 0.2.\l

4 Acetone 0.4 M

The runs were carried out at atmospheric pressure and room temperature.The abbreviations used in this table are: .\lSl'v methanesulionylperoxide; a-ester, a-naphthyl inethanesullonate; S-ester, B-naphthylmethanesulfonate.

The solution olmethanesulfonyl peroxide in the solvent was divided intotwo portions. Immediately. naphthalene dissolved in an equal volume ofsolvent was added to one and then the decrease in peroxide content withtime was followed. The M81 used in these runs were to 05% pure.

TABLE 11 Run number 1 2 3 4 5 ti Solvent Acetone Acetone NitrobeuzeueNitrobenzene Acetone Acetone Naphthalene:

0. 0. 261 0. 133 0. 260 0. 274 0. 254 0. U8 2. 04 l. 04 .2. 03 2. 141.00 0. 098 0. 204 0. 104 0. 203 0. .214 0. l'Jll MS 0. 200 0. 392 0.100 0. 380 0. .203 0. 190 1.05 2.07 1.00 2.00 1.18 1.00 0.105 0. 2070.100 0. 200 0.113 0.100 Na hthalene after reaction, g 0. 035 0. 075 0.0. aster formed:

weight g 0- 125 0- 280 0. 163 0. 268 0. 150 0. 16;! moles 0. 56 1. 26 0.73 1. 20 0. 70 0. 6x a.+fi-Ester formed:

weight g V l v 0. 14 0. 300 0. 180 U 278 0. 170 0. mrnoles .65 3 0.81 1.25 0. 77 0.74 Conv. of naphthalene, mole percent 72.0 Efficiency, toa-cster based on naphthalene, mole percent 80.0 Efficiency, to a-+B-ester based on naphthalene, mole percent 93 0 Yield of a-ester basedon MSP, mole percent Yield of B-ester based on MSP, mole percent Yieldof cz- +B-ester based on MSP, mole percent The runs were carried out atatmospheric pressure and room temperature. The abbreviations used inthis table are: MSI, bis-(methanesullonyl peroxide); a-ester, a-naphthylmethanesulionate; B-ester, fi-naphthyl methanesulfonate. The totalvolume of the reaction mixture was 10 ml.

The ratio between the alphaand betamethanesulfonates EXAMPLE 11 in thevarious reaction media shown in the Table 1 above indicate that thealpha ester forms in preference to the beta 65 Acetic acid was tested asa solvent for the naphthalene and ester such that the mole ratio of thealphato the betaester is bis-(methanesulfonyl peroxide) reactants.Reaction between greater than 10. bis-(methanesulfonyl peroxide) andacetic acid was observed;

Table 11 indicates that when the reaction between however, the reactionwith naphthalene proceeded at a much naphthalene andbis-(methanesulfonyl peroxide) is carried higher rate such that aceticacid could be used as a solvent. out using acetone as the solvent andapproximately equimolar 70 For example, in a solution of 0.37 Mbis-(methanesulfonyl amounts of reactants (0.1 M and 0.2 M), theefficiency of conperoxide) in acetic acid at room temperature, less than1 perversion to beta-naphthyl methanesulfonate ranged from 3 to cent ofthe peroxide reacted with the solvent in the first l0 13 mole percentbased on naphthalene while the efiiciency of minutes. Table 11] belowshows the reaction of naphthalene conversion to the alpha-ester underthese conditions was apwith bis-(methanesulfonyl peroxide) atatmospheric pressure proximately 80 mole percent. This is indicated byruns 1 and 75 and at room temperature using acetic acid as solvent.

TABLE III Run number 1 2 3 4 5 0 7 8 J 10 11 12 i3 SolvenL- AcOH A0011A00 11 AcOH AeOII AcOH AcOii A00 11 AcO ii AcOli AcOli Acoli Am) 11Volume oi reaction in 13 15 10 G 2 2 2 2 4 8 12 10 Reaction temp, C 23*223*2 23:2 23:2 23==2 23 :2 23*2 0 0 23= =2 23*2 23*2 23*) Reactantscharged naphthalen Weight, g 0. 480 0. 800 0. 522 0.800 0. 160 0. 160 0.160 0. 150 0. 100 0. 137 0. 137 0. 137 O. 137 Mmo1 3. 75 6. 25 4.08 6.25 1. 25 1. 25 1. 25 1. 25 1. 25 1.07 1.07 1.07 1.07 Gone. in reactionmixture, M. 0 289 0.417 0. 204 0. 625 0 208 0. 622 0. 622 0. 622 0. 6220. 268 O. 134 0. 089 0. 067 M SP:

Weight, g .1 0. 720 0.720 0.380 0. 360 0. 360 0.087 0.087 0.087 0. 0870. 210 0. 210 0.210 0.210 MmoL 3. 79 3. 79 2. 00 1. 89 1. 80 0. 46 0. 460. 46 0. 46 1.10 1.10 1.10 1. 10 Co no. in reaction mixture, M 0. 292 0.256 0. 100 0. 189 0. 315 0. 230 0.230 0. 230 0. 230 0. 276 0. 138 0.0920. 0611 Mole ratio, naphthalene to MSP... 1. 0 1. 6 2. 0 3. 2 0.6 2. 72. 7 2. 7 2. 7 1. 0 1. 0 1. 0 1. 0 Naphthalene after reaction:

Weight, g 0.052 0.300 0. 362 0.500 0. 039 0.048 0.048 0 048 0. 048 0.0320. 032 0. 034 0. 032 Mmol. 0. 41 2. 34 2. 82 3. 92 O. 0. 37 0.37 0. 370.37 0.25 0. 25 0. 26 0. 25 Conversion of naphthalene, moi

percent 89 63 32 37 76 70 70 70 70 77 77 75 77 a-Ester Formed:

Weight, g 0.411 0. 503 0.370 0. 375 0. 174 0. 080 0.080 0 064 0.066 0.123 0. 130 0. 136 0. 148 Mmol 1. 85 2. 27 1. 67 1. 69 0. 70 0.36 0. 360. 29 0.30 0. 55 0. 59 0.61 0.67 a- +B-Ester formed:

Weight, g 0. 458 0. 555 0. 410 0. 420 0. 392 0. 089 0. 089 0. 069 0. 0710. 131 0. 140 0. 148 0. 165 mol. 2. 06 2. 50 1. 84 1. 89 0. 87 0. 0. 400. 31 0. 32 0. 59 0. 63 0. 67 0. 74 Ratio of ato Hester. 8. 8 9. 9 9. 88. 5 9. 9 9. 0 9. 0 14. 0 15. 0 14. 0 15. 0 10. 0 9. 6 Efliciency, basedon Napthalene a-Ester moi percent 56 58 133 72 84 38 38 30 31 67 71 7681 a- +fl ester, mol percent 62 64 148 80 97 42 42 33 34 72 77 83 91Yield, based on MSP, of:

a-cster moi percent 49 60 84 00 42 78 78 63 65 50 54 55 61 a- +fi-esier,moi percent 56 66 92 100 46 87 87 67 70 54 57 61 6 The runs were carriedout at atmospheric pressure and room temperature except runs 8 and 0which were run at 0 C. The reaction time was 15 min- Abbreviations used;MSP, bis-(methenesull'onyl peroxide); a-ester, a-naphthylmethane-sulfonate; B-ester, fl-naphthyl methanesulionate.

The reactants were charged volumctrically using stock solutions inacetic acid. The weights charged are calculated from the analysis ofeach stock solution and the volume used. The MS? used to make the stocksolution was 95% pure. The figures listed are the weights of 100% MSP.

As can be noted from the table above the yield efficiency of alpha andbeta-naphthyl mcthanesulfonates based on bis- (methanesuifonyl peroxide)increased as the ratio of naphthalene to bis-(methancsulfonyl peroxide)was increased. For example, at a mole ratio of naphthalene to bis-(methanesulfonyl peroxide) of 3, the yield efficiency of total esterbased on bis-(methanesulfonyl peroxide) was greater than 99 percent.(Run No. 4). As the molar ratio of naphthalene to bis-(methanesulfonylperoxide) decreased to about 1, the yield efficiency of total esterbased on bis- (methanesulfonyl peroxide) decreased to about 55 percent.

Runs Nos. 6, 7, 8, and 9 indicate the results of reactions carried outat room temperature (23 2 2 C) and at 0 C. When the reaction was carriedout at 0 C the yields of the esters based on bis-(mcthanesulfonylperoxide) were lower than the yields obtained at room temperature, whilethe ratio of alphaester to beta-ester varied from 9 at room temperatureto 15 at 0 C.

Table No. 1V shows that the effect of the solvent, whether acetone oracetic acid, on the yield of esters based on bismethanesulfonylperoxide) is negligible.

The runs were carried out at atmospheric pressure and room temperature.Bis-(methanesulfonyl peroxide) is abbreviated MS? in this table.

EXAMPLE Ill Bis(methanesulfonyl peroxide) was prepared as described inExample 1 by the anodic oxidation of 10 M aqueous methanesulfonic acid.Runs were made in benzene solvent at atmospheric pressure at atemperature of 26 3 C with results described in Table V. As an exampleof how the process was carried out, in Run No. 2, 3.92 millimolcs (0.502grams) of naphthalene was dissolved in 0.33 moles (30 ml) of benzene.Solid bis-(methanesulfonyl peroxide) (3.70 millimoles) was added insmall portions to the solution. The concentration of the reactants tothe benzene solution was then approximately 3.13 molar. After tenminutes samples of the reaction were taken for analysis.

TABLE V Run Number 1 2 3 Reactants Charged Benzene: wt, g 26.26 25.9826.25 vol, ml 30 30 30 Naphthalene: wt, 3 0.251 0.502 0.754 mmol 1.963.92 5.89

MSP: wt, g 0.365 0.702 1.090 mmol 1.91 3.70 5.74 moi/liter 0.064 0.01230.191 Product Analysis PhMS: wt, g 0.024 0.049 0.038 mmol 0.140 0.2850.510 a-Ester: wt, g 0.300 0.600 0.940 mmol 1.35 2.70 4.24 a-B-Esterzwt, g 0.327 0.656 1.096 mmol 1.47 2.95 4.94 Ratio of afl-Estcrto PhMS 10.5 10.3 9.7 Ratio of ato fl-Ester l 1.3 10.7 6.0Yield-Efficiency based on MSP:

a-Estcr, 7c 71 73 74 Total Esters, 84 88 Runs were carried out atatmospheric pressure and 26 :2: 3C. MSP was added as a solid to thenaphthalene solution in benzene. The reaction time was 10 min.Abbreviations used: MSP, bis (methancsulfonyl peroxide); PhMS, phcnylmethancsulfonate; a-ester, a-naphthyl methanesulfonatc; fl-ester,fl-naphthyl methanesulfonate; total esters, PhMS B-cster B-estcr.

According to the results shown in Table V, when the reaction was carriedout at a mole ratio of naphthalene to bis- (methanesulfonyl peroxide) ofl, the yield efliciency of esters based on bis-(methanesulfonylperoxide) increased with the concentration of the reactant. At moleratios of benzene to naphthalene of 166, 83,and 55 respectively, theyield efficiencies of the total esters including phenyl methanesulfonatebased on bis-(methanesulfonyl peroxide) were 84, 88, and 95 molepercent. These results indicate that the reaction rate ofbis-(methanesulfonyl peroxide) with naphthalene is sufiiciently higherthan the reaction rate of bis-(methanesulfonyl peroxide) with benzene toallow it to be useful as a solvent in the process of this invention. Theuse of benzene as a solvent also presents some advantages over othersolvents in that the by-product formed by the oxidation of benzene withmethanesulfonyl peroxide has economic value. The reaction can thus becarried out at a mole ratio of naphthalene to bis- (methanesulfonylperoxide) of about 1 with a high yield of total esters. The benzene isconverted to phenyl methanesulfonate which is readily hydrolyzed tophenol, a valuable chemical product.

EXAMPLE IV A continuous reaction system for the oxidation of naphthalenewith bis-(methanesulfonyl peroxide) to the corresponding alpha naphthylester was devised. A reaction flask (500 ml Morton flask) with adecantation chamber was attached to the electrolytic cell described inExample 1. Aqueous methanesulfonic acid M) was passed through theelectrolytic cell where it was converted to a solution ofmethanesulfonic acid saturated with bis-(methanesulfonyl peroxide). Thissolution was then contacted with the immiscible organic phase(naphthalene and benzene) in a stirred reaction flask. 1n thedecantation chamber the electrolytic solution was separated from theorganic phase and recycled to the electrolytic cell. The results areshown in Table No. Vl.

To obtain high yields in the continuous system all the organic compoundsshould be removed from the electrolytic solution before it is recycledto the electrolytic cell as the naphthyl esters formed by the reactionof naphthalene and bis- (methanesulfonyl peroxide) are further oxidizedwhen allowed to come into contact with an excess of bis-(methanesul- Theruns were carried out at room temperature. Approximately 0.17 Faradayswas passed in each run (0.8 amps, 6 hr).

(")The naphthalene solution in benzene was placed in the reactor. Whenthe electrolysis was started the electrolytic solution was recirculatedwith the aid of a bellows pump. The two phases in the reaction flaskwere mixed with strong agitation.

()The MSP was separated in the fritted glass filter, then the electrolytic solution was recirculated to the reaction flask with no currentflowing through the cell. ()Abbreviations used: MSP,bis-(methanesulfonyl peroxide); MSA, methanesulfonic acid; naphthylesters, crand fl-naphthyl methanesulfonates.

EXAMPLE V in Example I. The results are shown in Table VII.

TABLE V11 Run Number 1 2(") 3() 4(') 5(") Reactant Charged Benzene: wt,g 26.16 26.23 26.19 42.5 43 vol, ml 30.0 30.0 30 50 50 Naphthalene: wt,g 0.513 0.514 0.503 0.900 0.780 mmol 4.0 4.0 3.93 V 7.00 6.10 mol/l 0.130.13 0.13 0.14 0.12 MSP: wt, g 0.761 0.754 0.765 1.300 1.280 mmol 4.004.00 4.00 6.85 6.75 mol/l 0.13 0.13 0.13 0.14 0.14 Product AnalysisPhMS: wt, g 0.114 0.119 0.106 0.056 0.060 mmol 0.660 0.695 0.615 0.3250.350 a-Ester: wt, g 0.660 0.582 0.62 0.98 0.94 mmol 2.98 2.63 2.77 4.414.23 a fl-Ester: wt, g 0.72 0.64 0.65 1.08 1.02 mmol 3.22 2.90 2.93 4.864.60 Yield Efficiency based on MSP: a-Ester, 75 66 69 71 68 TotalEsters, 7c 97 89 76 73 Runs were carried out at atmospheric pressure androom temperature (26 i 3C). Reaction time was 45 min. Abbreviationsused: MSP, bis- (methanesulfonyl peroxide); PhMS, phenylmethanesulfonate; cr-ester, a-naphthyl methanesulfonate; fi-ester,fi-naphthyl methanesulfonate; total esters, PhMS a-ester B-ester.

(")The experiment was carried out in the presence of a water phase.(")The experiment was carried out in the presence of a 10M MSA phase.

()The experiment was carried out using a naphthalene in benzene solutionsaturated with water.

(")The experiment was carried out using a naphthalene in benzenesolution saturated with 10 M MSA.

EXAMPLE Vl Nitrobenzene was used as the solvent for the naphthalene andbis-(methanesulfonyl peroxide) reactants. No reaction of thenitrobenzene with the bis-(methanesulfonyl peroxide) was observed.Alpha-naphthyl methane methanesulfonate was obtained in a yield, basedon bis-(methanesulfonyl peroxide) of 69 percent.

1 claim:

1. A process for oxidizing naphthalene to form naphthylmethanesulfonates in a ratio of alpha-methanesulfonate tobeta-methanesulfonate of at least about 8 to 1, said process comprisingcontacting naphthalene with bis(methanesulfonyl) peroxide at a molarratio of naphthalene to bis(methanesulfonyl) peroxide of between about0.521 and about 10:1 at a temperature of between about 0 C. and about 50C. in a solvent selected from the group consisting of benzene,nitrobenzene, toluene, dioxane, acetic acid, and acetone, theconcentration of naphthalene being between about 0.01 moles per literand about 0.6 moles per liter.

2. A process according to claim 1 wherein:

the temperature is between about 15 C. and about 40 C.;

and

the bis(methanesulfonyl)peroxide is employed in a concentration ofbetween about 0.05 moles per liter and about 0.2 moles per liter.

2. A process according to claim 1 wherein: the temperature is betweenabout 15* C. and about 40* C.; and the bis(methanesulfonyl)peroxide isemployed in a concentration of between about 0.05 moles per liter andabout 0.2 moles per liter.